Retractable wing knee



Sept. 15, 1959 M. H. MATER RETRACTABLE WING KNEE Filed Nov. 17, 1958 FIGJ INVENTOR.

MILTON H. MATER BY BUCKHORN, CHEATHAMXBLORE ATTORNEYS i" i l d- United States Patent RETRACTABLE WING KNEE Milton H. Mater, Corvallis, Oreg.

Application November 17, 1958, Serial No. 774,221 2 Claims. (Cl. 143-122) My present invention comprises a retractable wing knee for sawmill carriages. The purpose of the present invention is to provide a supplementary knee which may be added to one of the usual knees of a sawmill carriage for the purpose of supporting crooked or springy logs, or cants.

A further object of the present invention is to provide such a device which may be actuated for utilization when necessary, or withdrawn to a retracted poistion when not needed, which device will not interfere with the action of the ordinary sawmill knee.

The objects and advantages of the present invention will be more readily understood 'by reference to, the following specification taken in connection with the accompanying drawings wherein like numerals refer to like parts throughout and in which a preferred form of the present invention is described and illustrated.

In the drawings,

Fig. 1 is a plan view of a sawmill carriage having the present invention mounted thereon;

Fig. 2 is a plan view, on an enlarged scale, of the retractable wing knee mounted in position of use;

Fig. 3 is a side view looking from the plane of the line 3-3 of Fig. 2; and

Fig. 4 is an end view looking from the plane of the line 44 of Fig. 3.

A conventional sawmill carriage is illustrated in Fig. l, the same comprising a sturdy frame supported by wheels 11 engaging a track 12 and opposed wheels (not shown) engaging a track 13. The carriage is reciprocated longitudinally of the rails by suitable means such as exemplified by the cables 14 and 15. A plurality of head blocks 16 is mounted transversely on the carriage and a plurality of knees 17 is respectively mounted upon and guided by the head blocks for movement toward and away from the plane of the saw (not shown). The knees are controlled by means of a set shaft 18 suitably connected thereto in any of several well-known fashions, which shaft is rotated by means of a sprocket chain drive 19 and motor 20 mounted on the frame of the carriage. The forward face of each knee is vertical and knee dogs such as indicated at 21 project therethrough so as to be capable of engaging and holding a log 22 or other wooden member to be sawed into cants or planks. As indicated in Fig. 1 a log sometimes may be so shaped as to prevent the knee dogs 21 from engaging the log unless the sawyer releases and replaces the log, a time consuming operation. In such instances the retractable wing knee of the present invention may be brought into use. Also, in the event a small and springy log is being cut it may be desired to support portions of the log intermediate the usual knees, for which purpose the wing knee of the invention may be brought into use. One wing knee is herein illustrated but it is to be appreciated that others may be employed, for example, one in association with each carriage knee, or even two on the opposite sides of a single carriage knee.

The retractable wing knee of the present invention "ice comprises a parallelogram linkage frame having four linkage sides of substantial height pivotally connected by vertical pivots at the corners of the frame. As illustrated, the frame comprises a first side 25, an opposite side 26 providing the retractable wing knee itself, and the connecting parallel sides 27 and 28. Side 25 is pivotally connected to the sides 27 and 28 respectively by vertical pivots 29 and 30, and the knee 26 is pivotally connected to the sides 27 and 28 respectively by vertical pivots 31 and 32. The pivots are conveniently mounted in ears, such as indicated at 33, welded to the respective plates 25 and 26. Sides 27 and 28 are conveniently formed as rectangular plates having their ends shaped to embrace the pivots. It is to be appreciated that side 25 may be conveniently mounted in vertical position on a side of the knee 17 so as to support the side 26 laterally from the knee. It is also to be appreciated that the pivots 29 and 30 may be mounted directly upon the knee 17, but that mounting them upon a plate such as illustrated eliminates the necessity of accurately locating the pivots 29 and 30 so as to space them the same distance apart as the pivots 31 and 32.

A bracket 40 is conveniently mounted upon the plate 25 adjacent the pivot 30, and a bracket 41 is conveniently mounted upon the plate 27 adjacent the pivot 31. A piston and cylinder device 42 comprising a piston 43 and a cylinder 44 is pivotally connected between the brackets 40 and 41 so as to lie in a horizontal position extending diagonally across the parallelogram frame. The device is a conventional double acting piston and cylinder device which, when extended as illustrated in full line in Fig. 2, causes the parallelogram frame to assume a right angle relationship, in which position side 28 is limited by the bracket 40 and side 26 is limited by the bracket 41. As illustrated in dash line in Fig. 2, the frame assumes a rhomboidal shape when the piston 43 is retracted.

The forward vertical edge of side 26 has aflixed thereto a vertical plate 46 forming the face of the retractable wing knee. When the knee is projected this plate 46 is advanced to the region of the plane of the face of the knee 17, and it may be retracted to various positions behind said plane. An elongated, upper slot 47 and a shorter, lower slot 48 are provided in the face plate 46. An upper dog 49 extends through slot 47 and a lower dog 50 extends through slot 48, the dogs forming the respective tips of upper and lower dog levers 51 and 52. The lower dog lever 52 is pivotally connected to plate 26 by a pivot 53, and is limited in its downward move ment by an abutment 54. A vertical link 55 extends upward from the pivot 53 and a pivot 56 thereon is pivotally connected to the inner end of the dog lever 51. A cylinder 57 is pivotally mounted in upright position on a pivot 58 mounted on the lower dog lever 52. A piston 59 extending from the cylinder is pivotally connected to an intermediate portion of the upper dog lever 51. The cylinder 57 is positioned in an opening in the plate 26 so that the dog levers 51 and 52 may be closely adjacent the plate. A spring 66 is tensioned between the upright link 55 and a forwardly spaced portion of the plate 26 whereby the upper dog lever 51 is urged forwardly. The forward movement of the upper dog lever is limited by a pin 67 which bears against a guide 68 mounted on the rear surface of the knee plate 46. When the piston 59 is extended the dogs are separated, and when retracted the dogs are caused to bite into the surface of an adjacent log. The dog levers 51 and 52 and the associated link 55, spring 66, cylinder 57 and piston 59 constitute dogging means mounted upon the retractable wing knee. It is to be appreciated that such dogging means may be of any suitable type.

It will be appreciated that the construction of the retractable wing knee is relatively light, since it does not have to carry the main load, but merely supplements the regular sawmill carriage knees. The light construction thereof does not add materially to the load on the knee setworks mechanism. H p

J Iphave illustrated the device of the presentinvention as being capable of advancing beyond theplane of the knee so as to engage a crooked log as illustrated. I have found, however, that the greatest use of the present invention is in supporting the last section of a log being sawn, or a narrow can which, while normally straight may spring between the knees when subjected to the forces acting upon it in the sawmill. In such cases it is preferred to so mount the wing knee that the face of the wing knee lies in the plane of the regular knees when the parallelogram linkage is fully extended. Alternatively, stops may be so arranged as to limit the forward movement of the wing knee to this plane. Either alternative eliminates any necessity of accurately adjusting the position of the knee in order that it may properly engage springy but straight cants or logs.

Having illustrated and described the present invention, it will be apparent to those skilled in the art that the same permits of modifications in arrangement and detail. I claim as my invention all such modifications as come within the true spirit and scope of the following claims.

I claim:

, 1. A retractable wing knee for mounting on a sawmill carriage knee comprising a parallelogram linkage frame having four linkage sides of substantial height pivotally connected together by pivot means at the corners of the frame, one of said linkage sides being mountable vertically on a side surface of a sawmill carriage knee so that said pivots are maintained in vertical relation, a piston and cylinder device mounted horizontally within said frame, said device extending along a diagonal of said frame and being pivotally connected at its ends to said frame, and dogging means mounted on the side of said frame opposite said one side.

2. A retractable wing knee comprising a pair of rectangular plates, a first pair of pivot means adapted to be mounted vertically in spaced apart relation on a side of a sawmill carriage knee, said first pair of pivot means respectively mounting said plates so as to extend laterally from said sawmill carriage knee, a second pair of pivot means mounted vertically at the respective outer ends of said plates, a wing knee pivotally connected to said plates by said second pair of pivot means, said References Cited in the file of this patent UNITED STATES PATENTS 2,661,779 Saunders Dec. 8, 1953 2,850,130 Mater Sept. 2, 1958 FOREIGN PATENTS 668,930. France July 23, 1929 

